This invention relates to a thermo-transfer printer capable of utilizing a jointed color ink sheet or ribbon.
The description will be first made as to a method for manufacturing a conventional ink sheet in conjunction with FIGS. 9 and 10. FIG. 9 is a view illustrating a method for manufacturing a conventional ink sheet and FIG. 10 is a view illustrating a conventional ink sheet.
In FIG. 9, 1 is a jumbo roll, 2 is an ink sheet used in a thermo-transfer printer and 3 is a defect portion.
One roll of ink sheet for use in a thermo-transfer printer is prepared by cutting a roll 1 of ink sheet called a jumbo roll into sections of a predetermined length corresponding to an ink sheet roll. When a defect is found in the sheet section as shown in FIG. 9, one complete section corresponding to one roll of ink sheet is discarded or disposed of and another new section corresponding to one roll is cut from the jumbo roll. FIG. 10 illustrates the ink sheet section corresponding to one roll.
In FIG. 10, it is seen that the ink sheet 2 is attached to bobbins 4 at the opposite ends and yellow ink (Y) is provided with a Y mark 5, magenta ink (M), cyan ink (C) and black ink (BK) are provided with M, C and B marks 6, respectively, and an EOI (End Of Ink) mark 7 is provided at the end of the ink sheet. Reference numeral 8 is a transparent tape.
Then, the operation of a conventional thermo-transfer printer will be described in conjunction with FIGS. 11 and 12. FIG. 11 is a flow chart showing the operation of the conventional thermo-transfer printer. FIG. 12 is a diagram illustrating a relative relationship between the conventional ink marks and an ink mark sensor of the conventional thermo-transfer printer.
In FIG. 11, in a step S1, the ink sheet 2 is first started to be wound and the judgement whether or not it is the Y mark 5 is made in a step S2. In a step S3, the Y mark 5 is searched for until time-out when it is not the Y mark 5. In a step S4, when the time-out is reached without finding the Y mark 5, it is judged to be a jam error. On the other hand, in a step S5, the index of the ink sheet is completed when the Y mark 5 is found.
In FIG. 12, in a step S10, the ink mark sensor searches for the Y mark 5. In a step S11, a mark edge is detected. In a step S12, the judgement is achieved at the center of the mark as to the M, C or BK mark 6. In a step 13, the Y mark 5 is again searched for. In a step S14, the mark edge is detected. In a step S15, the judgement is achieved at the center of the mark as to the Y mark 5 to complete the search.
With the conventional ink sheet, the roll must not be broken or separated. Therefore, when a defect is generated during the manufacturing of a roll, that roll in its entirety is wasted. While the yield of the ink sheet can be increased by removing the sheet portion with a defect and joining a fresh ink sheet to form a complete roll of the ink sheet, the ink sheet cannot be precisely joined together at the sheet portion where the ink mark changes because of the simplicity of the sheet joining operation. Therefore, the ink sheet must be joined by an adhesive tape.
However, the conventional thermo-transfer printer cannot use a color ink sheet with a joint. Accordingly, it is desirable to provide a color printer in which a color ink ribbon with a joint can be used.